Augustus often was ill for many weeks to months with various ailments. The most famous example is in 23 BCE where he almost died. But during the civil war he often arrived a few days late for battle due to being held up at camp being ill. It is noted he died at age 70 from the same illness that plagued him his entire life but I cannot find a good source as to what that illness is.

You are right, there are some descriptions of Augustus' physical condition. The most popular one might be Sueton, Aug. 80-81 with a number of different physical deficiencies. However, I would generally agree with u/cjt09 in his assessment that all of this doesn't necessarily indicate a single cause.

Apart from that Sueton is well known for his detailed descriptions of the physical condidtions of his subjects - and in almost all cases he paints quite a disastrous picture. (This is, by the way, a model case for his shadowbox style of writing - he systematicly works himself through the ever same topics for each portrayed person.) This has often been undestood as a literary topos that aims for entertaining his audience by stressing "every day topics" like illness, flaws of character and the like. (The FAQ of this sub are an exellent example that these topics are still very interesting ones for most of the people.) Another motivation for these depictions can be seen in the contrast between a weak, fragile body on the one hand and great mental abilities and political archievements on the other hand. This can for instance also be seen in the description of (greek) philosophers. In the light of the above, I think we have to be careful to interpret these aspects in Sueton as direct historical sources for the physical conditions of the persons portrayed by him.